Max mannesman ist



(ModeL) v M. MANNESMANN. MANUFACTURE OF SEAMLESS TUBES.

Patented Apr. 26, 1887.

Waxy.

UNITED STATES PATENT ()FFICE.

MAX MANNESMANN, OF REMSGHEID, GERMANY.

MANUFACTURE OF SEAMLESS TUBES.

EPECIFICATION forming part of Letters Patent No. 361,960, dated April 26, 1887.

Application filed April 1; 1887. Serial No. 233,245. (ModclJ Patented in Italy January 26, 1886. No. 7,925 in Lnxeinburg June 20. 1886, N0. 1'04; in Belgium August 14, 1886, No. 54,F57; in Spain August Q1, 1886, No. 9,537. and in Austria-Hungary September 1?, 1886.

To all whom it may concern:

Be it known that 1, MAX MANNEsMANN, of Remscheid, Germany, have invented certain Improvementsin Apparatus for Enlarging Metallic Tubes, of which the following is a specification.

This invention relates to apparatus for enlarging the sizes of metallic tubes or hollow metallic ingots by progressively compressing the shell of the tube or hollow ingot upon the surface of a conoidal mandrel and simultaneously forcing the metal to move from the smaller end or point of the conoidal mandrel toward and over the base of the mandrel. The apparatus for accomplishing these purposes, which is embraced in the present invention, consists of a conoidal mandrel having the desired taper and dimensions, and in combination therewith two or more diagonally/acting conical or conoidal rolls, the working-faces of which diverge from the place where they compress the shell of the tube upon the smaller part of the mandrel to or beyond the place where the greatest enlargement in the size of the tube is effected and where its shell becomes thinnest. Y

As diagonal rolling machines are well known, it is deemed sufficient to herein show only those operative-parts of the apparatus which in their construction and mode of operation are comprehended in the present invention.

The accompanying drawings of tube-enlarging apparatus embodying the invention are as follows:

Figure 1 is a top view of a pair of conoidal enlarging-rolls arranged on either side of a conical mandrel, and showing in central longitudinal section a tube or hollow ingot in process of being enlarged in size. Fig. 2 is a transverse vertical section taken through the line at a" on Fig. 1.

The tube-enlarging apparatus shown in the drawings consists of a pair of conoidal rolls, A a, arranged, respectively, upon opposite sides of a conical mandrel. The vertical planes of the axes of the rolls A a are parallel, but their axes are inclined relatively in opposite directions. At their larger ends, A a, the

0, enter the opening b through the center of V the blank.

Instead of two conical rolls, there may be employed three, or even four, such rolls, so ar ranged as to bear upon different sides of the blank, which by their action is forced over the conical mandrel.

Vhen more than two rolls are employed, they serve to centralize the blank, and when only two rolls are employed horizontal guides must be provided to support the blank and hold it in the proper horizontal plane during its passage through the rolls. Such guides, however, are common in diagonal-rolling apparatus, and it is not, therefore, deemed necessary to show them or describe them in detail.

Blanks or hollow ingots preparatory to being passed between the rolls are, if necessary, heated more or less, according to the material of which they are composed. Steel and iron blanks require to be heated to a higher temperature than blanks composed of copper or other comparatively soft and ductile metals'or alloys.

By a single passage between the rolls the blank or hollow ingot is enlarged in size and made to acquire an internal diameter which is approximately determined by the diameter of the base of the conical mandrel, and a thickness of shell which is determined by the distance between the rolls and the part of the mandrel which is nearest to the working-faces of the rolls.

As will be seen, the taper of the conical mandrel O is slightly less acute than the taper of the conical rolls. It hence results that during the passage of the blank through the apparatus its shell is progressively diminished in thickness by the continued impingement of the working-faces of the rolls upon the exterior of the portion of the shell which is interiorly supported upon the conical mandrel.

It may be understood that for the purposes 50 rolls are slightly rounded or chamfered to faof the invention the rolls may be so shaped I00 that their lines of impingement upon the blank are either straight or curved, and similarly that the mandrel may have its surface curved in the direction of its length, the only essential being that the mandrel shall have such a taper as will suitably provide for the amount of reduction in the thickness of the shell to be produced by the compression of the shell upon the surface of the mandrel.

What is claimed as the invention is- Y 1. The improvement in the art of enlarging tubes or hollow metallic ingots herein described, which consists in progressively forcing such tubes to move against the smaller part and over the base of a conical or conoidal mandrel, and at the same time compressing the shell of such tube or blank upon the surface of the said mandrel, and thereby gradually reducing the shell in thickness, while enlarging it in both internal and external diameter by means of diagonally-acting rolls, the lines of of such shape relatively to the portions of the Working-faces of the rolls which impinge upon the blank that the distance between the surface of the mandrel and the said portions of the rolls, respectively, gradually diminishes from the smaller end of the conical or conoidal mandrel toward the larger part thereof.

MAX MANNESMANN.

Witnesses:

A. M. J ONES, M. L. ADAMS. 

